The present invention relates to a slitting device for cutting a sheet material into strips, and a method therefor.
Japanese Patent Application First Publication No. 6-55224 discloses an apparatus for forming corrugated-fin strips for use in a heat exchanger such as a radiator. FIG. 7 shows the apparatus including a tension device 2 for applying tension to a fin material 1, a slitting device 3 for cutting the fin material 1 into two parallel strips, a corrugating device 5 for forming corrugations (fins) in the strips, and a feed device 7 for feeding the strips with the corrugations. Reference numeral 100 denotes a direction of process flow. The fin material 1 fed to the slitting device 3 is cut into the two strips by upper and lower cutting rollers 4, 4. A pair of corrugation cutters 6, 6 of the corrugating device 5 cooperate to form corrugations in the strips of the fin material 1. The strips with corrugations are fed to the feed device 7 in which a pair of feed rollers 8, 8 compress the strips with corrugations for adjusting a fin pitch. Thus, two corrugated-fin strips 9 having the adjusted fin pitch are formed. The two corrugated-fin strips 9 are then fed to a cutting device (not shown) and cut into a predetermined length.
However, in the related art described above, the fin material 1 straightly extends to the corrugating device 5 through a gap between the cutting rollers 4, 4 of the slitting device 3, so that the fin material 1 tends to slip relative to the cutting rollers 4, 4. This will cause difficulties in cutting the fin material 1 into the strips.
In order to suppress the occurrence of slippage of the fin material 1, it has been proposed to wind the fin material 1 on the cutting rollers 4, 4 so as to form a generally S-shaped path of the fin material 1 as viewed in the axial direction of the cutting rollers 4, 4. However, if the fin material 1 is wound on the cutting rollers 4, 4 in such the manner, the fin material 1 will meander by the following reason. Each of the upper and lower cutting rollers 4, 4 has a larger outer-diameter cutting portion and a smaller outer-diameter guide portion axially adjacent to the larger outer-diameter cutting portion. The larger outer-diameter cutting portion of the upper cutting roller 4 is opposed to the smaller outer-diameter guide portion of the lower cutting roller 4, and the smaller outer-diameter guide portion of the upper cutting roller 4 is opposed to the larger outer-diameter cutting portion of the lower cutting roller 4. The fin material 1 introduced into the gap between the upper and lower cutting rollers 4, 4 is cut at outer peripheral edges of the larger outer-diameter cutting portions which are located axially adjacent to each other. The difference between the outer diameters of the cutting portion and the guide portion of each cutting roller 4 will cause meander of the fin material 1.
There is a demand to solve the above-described problems in the related art. An object of the present invention is to provide method and device for cutting a sheet material into strips which is capable of preventing the occurrence of meander of the sheet material and slippage thereof relative to cutting rollers upon cutting the sheet material into the strips, and to provide a corrugated-fin strips forming apparatus using the device.
According to one aspect of the present invention, there is provided a slitting device for cutting a sheet material into strips, comprising:
a first cutting roller rotatable about a first axis, the first cutting roller including a first cutting edge and a first recessed portion circumferentially extending and radially recessed from an outer circumferential surface thereof;
a second cutting roller rotatable about a second axis parallel to the first axis, the second cutting roller including a second recessed portion circumferentially extending and radially recessed from an outer circumferential surface thereof and a second cutting edge axially adjacent to the first cutting edge and cooperating therewith for cutting the sheet material into the strips;
a first guide roller disposed coaxially with the first cutting roller and adjacent thereto and opposed to the second cutting roller, the first guide roller including first cutout portions circumferentially extending and axially opposed to each other on an outer circumferential surface thereof and a first projection defined by the first cutout portions and opposed to the second recessed portion of the second cutting roller, the first guide roller cooperating with the second cutting roller to define a first space for a first strip of the strips; and
a second guide roller disposed coaxially with the second cutting roller and adjacent thereto and opposed to the first cutting roller, the second guide roller including second cutout portions circumferentially extending and axially opposed to each other on an outer circumferential surface thereof and a second projection defined by the second cutout portions and opposed to the first recessed portion of the first cutting roller, the second guide roller cooperating with the first cutting roller to define a second space for a second strip of the strips;
the first cutting roller, the first guide roller, the second cutting roller and the second guide roller having a same outer diameter.
According to a further aspect of the present invention, there is provided an apparatus for forming corrugated-fin strips from a sheet material, comprising:
a slitting device for cutting the sheet material into strips, the slitting device comprising:
a first cutting roller rotatable about a first axis, the first cutting roller including a first cutting edge and a first recessed portion circumferentially extending and radially recessed from an outer circumferential surface thereof;
a second cutting roller rotatable about a second axis parallel to the first axis, the second cutting roller including a second recessed portion circumferentially extending and radially recessed from an outer circumferential surface thereof and a second cutting edge axially adjacent to the first cutting edge and cooperating therewith for cutting the sheet material into the strips;
a first guide roller disposed coaxially with the first cutting roller and adjacent thereto and opposed to the second cutting roller, the first guide roller including first cutout portions circumferentially extending and axially opposed to each other on an outer circumferential surface thereof and a first projection defined by the first cutout portions and opposed to the second recessed portion of the second cutting roller, the first guide roller cooperating with the second cutting roller to define a first space for a first strip of the strips; and
a second guide roller disposed coaxially with the second cutting roller and adjacent thereto and opposed to the first cutting roller, the second guide roller including second cutout portions circumferentially extending and axially opposed to each other on an outer circumferential surface thereof and a second projection defined by the second cutout portions and opposed to the first recessed portion of the first cutting roller, the second guide roller cooperating with the first cutting roller to define a second space for a second strip of the strips,
the first cutting roller, the first guide roller, the second cutting roller and the second guide roller having a same outer diameter, a corrugating device for forming corrugations in the strips of the sheet material; and
a feed device for feeding the strips with corrugations.
According to a still further aspect of the present invention, there is provided a method for cutting a sheet material into strips, comprising:
guiding the sheet material in a first direction so as to form a generally S-shaped path of the sheet material as viewed in section taken along the first direction; and
cutting the sheet material into the strips parallel to the first direction at a cutting position spaced from opposed ends of the sheet material in a second direction perpendicular to the first direction, while supporting the sheet material from opposite sides of the sheet material at support positions located in a spaced relation in the second direction, the cutting position being located between the support positions.